Solenoids have been used to provide a number of functions in automotive applications including, but not limited to automotive transmission systems. Solenoids are typically required to exhibit fairly precise current/pressure performance characteristics (e.g., solenoid characteristic curve coefficients) so as to be operationally compatible with the design and/or operating conditions of the other components of the vehicle, including but not limited to those of the transmission system. This is especially true with respect to recently developed transmission systems that rely heavily on solenoids for clutching functions, such as BorgWarner's Dual Clutch Transmission (DCT) system.
Some manufacturers and/or assemblers do not employ any calibration techniques on the transmission modules containing solenoid(s) therein. While this does not involve any need for data transfer, and the module is serviceable, there may be resulting wide variations in the solenoid characteristic curves. This may adversely affect solenoid performance, and thus affect the overall performance of the vehicle. Accordingly, there has been increased interest in the automotive industry with respect to the calibration and/or transfer of solenoid characteristic curve coefficients.
One method includes what is generally referred to as autonomous calibration, i.e., a transmission control unit (TCU) “sweeps” solenoid current and measures pressure with on-board sensors. While this method does not involve any need for data transfer, and the module is serviceable, it does require on-board sensors for each and every solenoid, as well as requiring a calibration algorithm for the TCU.
Another method includes what is generally referred to as original equipment manufacturer (OEM) end-of-line calibration, i.e., the manufacturer performs the calibration function once the TCU and valve body are assembled together. While this method involves the use of supposedly pre-existing test equipment and established methodology, it does require the OEM to perform the testing and program the TCU, and the TCU and valve body must remain together and thus the module is not serviceable. More specifically, the entire module must be replaced, as individual solenoids are not serviceable.
Still another method includes what is generally referred to as supplier end-of-line calibration, i.e., the supplier, as opposed to the OEM, performs the calibration function once the TCU and valve body are assembled together. While this method also involves the use of supposedly pre-existing test equipment and established methodology, it does require the OEM to send the module to the supplier, as well as requiring the supplier to perform the testing, and the TCU and valve body must remain together and thus the module is not serviceable. More specifically, the entire module must be replaced, as individual solenoids are not serviceable.
Therefore, there exists a need for new and improved calibration data transfer systems and methods for using the same, especially with respect to solenoids employed in transmission systems.